过滤芯的数据结果通过性能之间

Question

我现在有核心数据成功返回所有结果的特定实体名为事件：

NSManagedObjectContext *context = [delegate managedObjectContext]; 
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Event" 
                inManagedObjectContext:context]; 
NSFetchRequest *request = [[NSFetchRequest alloc] init]; 
[request setEntity:entityDescription]; 

NSError *error; 
NSArray *fetchResults = [context executeFetchRequest:request error:&error]; 

现在日历的时间绘制我需要获取那些开始日期事件在本月和结束日期之前或之前也在本月或之后。

我相信答案与NSPredicate有关，但我对此还不够熟悉，却没有让它屈服于我的意愿。

Answer 1

更改条件的谓词：

NSDate * firstDateOfMonth = [self returnDateForMonth:month year:year day:2]; 
NSDate * lastDateOfMonth = [self returnDateForMonth:month+1 year:year day:1]; 

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(startDate => firstDateOfMonth) and (endDate <= lastDateOfMonth)”]; 

NSManagedObjectContext *context = [delegate managedObjectContext]; 

NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Event"            inManagedObjectContext:context]; 

NSFetchRequest *request = [[NSFetchRequest alloc] init]; 
[request setEntity:entityDescription]; 
[request setPredicate:predicate]; 

NSError *error; 

NSArray *fetchResults = [context executeFetchRequest:request error:&error];